Alderson counted only 13 open spots on 40-man rosters, which will lead to players getting traded, designated for assignment and released.

"As these free agents begin to sign, there's going to be a lot of roster churn among the teams and other opportunities," he said Thursday on a chilly winter morning at Citi Field. "So it's going to be interesting the next two or three weeks."

Alderson spoke with invited fans as the Mets' equipment truck was loaded for the trip to training camp in Port St. Lucie, Florida. In a sign of baseball economics, club executives told him to speak with the media and face cameras while standing in front of the spot of the truck containing a sponsor logo.

Moustakas is among the nine free agents who turned down $17.4 million qualifying offers from their former teams. A new club signing one of those players would incur penalties.

"It's possible that what he'll end up doing is signing a one-year contract. I don't know," Alderson said. "There are a couple of things involved there. One is draft-choice compensation and the loss of international pool money, both of which are key to us improving what is now a less-than robust farm system."

With a slow free-agent market, teams appear to be more deliberate in their negotiations.

"There's a reason that the market has been stagnant, and it's not just because clubs aren't spending money," Alderson said. "It's because players aren't prepared to sign contracts currently given where the marketplace is. So I'm sure that will change at some point, one way or the other. Things will loosen up on one side or both. But right now, it isn't just clubs that are not signing players, it's players not signing contracts. They're as cautious as some teams have been."

Alderson said 44-year-old pitcher Bartolo Colon was not likely to return to the Mets, where he became a fan favorite from 2014-16.

"It made the rest of his career a lot more memorable, the fact that he was a Met," Alderson said. "At some point he's going to fall off the cliff. It's like playing old maid. The game ends at some point, even for him."

He was surprised when a fan asked him about pitcher Jenrry Mejia, given a lifetime suspension in February 2016 following his third failed test for performance-enhancing drugs.

"My specific goal is don't flunk a drug test for the next year-and-a-half or so, see if you can get reinstated," Alderson said. "That's a low threshold, I know, but that's where we are."